Dry chemical injector



1967 R. w. PAYNE DRY CHEMICAL INJECTOR 2 Sheets-Sheet 1 Filed Aug. 14, 1964 INVENTOR. A244? fll Pm M BY Feb. 28, 1967 PAYNE 3,306,376

DRY CHEMICAL INJEC'IQR Filed Aug. 14, 1964 2 Sheets-Sheet 2 I N VENTOR. PAM/e M 9071 5 United States Patent Ofiice 3,306,376 Patented Feb. 28, 1967 This invention relates to a dry chemical injector for oil and gas wells.

. It has been the practice in drilling oil and gas wells to force air or gas down into the well bores for the purpose of circulating upwardly and removing cuttings from the well bores. This air or gas flow has also been used to carry dry chemicals, in powder or flake form, such as metallic soaps containing such as aluminum, calcium, zinc, or lithium stearate, down through the drill string, for purposes, such as:

(a) In the event of entry of water intothe well bore, from porous formation, preventing gumming and balling up of formation cuttings and serving as anti setting agents, and so as to coat the cuttings, so as to enable the air or gas streams to clear the well bore;

(b) To lubricate bearings and drill bits and to reduce torque in the rotary drill string, using graphite in powder or flake form;

(c) Speed up the drying of a wet bore, using silica gel;

(d) To reduce torque in a drill string resulting from a crooked well bore or a weeping formation or formations, using combinations of the above mentioned chemicals.

, The injecting means, whether using air or gas, thus far used, has been crude, inefficient, and in the case of use of gas, dangerous and diflicult to handle.

The primary object of the present invention is the provision of an efiicient, safe, economical chemical injector of the kind indicated above, wherein the flow of chemicals is accurately metered, within a readily controlled range of flow.

Another object of the invention is the provision of an injector of the character indicated above, which involves a substantially closed system, wherein an air motor driven anger is employed to move the dry chemicals from a hopper to the drill string, in such a manner that the chemicals are fed into the air or gas stream, by controlled rates of rotation of the auger, there being no differential of air or gas pressure, at either end of the auger, the speed of rotation of the auger being accurately controllable within a specified range of, for example, 2 to 35 R.P.M.

In the drawings:

FIGURE 1 is a schematic side elevation showing an injector assembly of the present invention connected to an air or gas hose which is connected to the upper end of the drive of a drill string, which extends down into a well bore;

FIGURE 2 is a schematic top plan view of FIGURE 1, on a reduced scale;

FIGURE 3 is a side elevation, on an enlarged scale, of the injector;

FIGURE 4 is a vertical transverse central section taken through FIGURE 3, and showing, in phantom lines, members connected thereto;

FIGURE 5 is a central vertical transverse section taken through FIGURE 4 on the line 5-5; and

FIGURE 6 is a top plan view of FIGURE 4.

Referring in detail to the drawings, there is shown (in FIGURE 1) a well head 10, above the ground G, on the upper end of a well casing 12, which extends downwardly into a well bore 14. A drill string 16 extends concentrically down through the casing 12 and extends up above the well head 10, and through a drive member 18, supported on a table 20. An air or gas discharge :ipe 22 leads laterally from the head 10 for discharging from the casing 12, cuttings from the well bore, present in the discharged air or gas.

An air or gas hose 24 is connected, at one end, to the upper end of the drill string 16, and is connected, at its other end, to the upper end of a vertical arm 26 of a flow pipe 28 through which air or gas is forced, from a suitable source, such as a compressor 30, in the direction of the arrows, in FIGURES 1 and 6, through a pipe 29.

An injector 32 is interposed in the flow pipe 28, between the compressor 30 and the vertical arm 26 thereof. The injector 32 comprises a vertically elongated cylinder or hopper 34, having a reduced diameter upper portion 36, the open upper end of the portion 36 being closed and sealed by a cap type head 38. The head 33 incorporates a central packing gland 40, through which works a rod 42 having a horizontal handle bar 44, on its upper end. The rod 42 extends down through the cylinder 34 and has fixed, on its lower end, a horizontal circular baflie plate 46, which is smaller in diameter than the inside diameter of the cylinder. The bafile plate 46 defines, with the side wall 48 of the cylinder, an annular controlled discharge channel 50, for comminuted chemical material contained in the cylinder 34, and which is to be controllably discharged into the flow pipe 28.

The cylinder 34 is upstanding on a ground-support frame 52, having parallel spaced side members 54, and cross members 56, the frame being substantially wider than the cylinder, as shown in FIGURE 6.

'The cylinder 34 has a concave-convex bottom wall 58, seen in FIGURE 5, which is mutilated and extended to form a horizontal transverse centrally located auger tube which extends beyond opposite sides of the cylinder 24-, and opens, at its top, as indicated at 62, in FIGURE 4, to the lower part of the cylinder, so as to receive chemical material, via the channel 50.

The output or discharge end of the auger tube 60 is open, as indicated at 64, but its other end is closed by an adjustable packing gland 66, through which turns an elongated, reduced diameter auger shaft 68, the latter extending from the adjacent end of an auger screw '70 which works closely in the tube 60.

Fixedly supported on cross members of the frame 52, is a pair of longitudinally spaced bearings 72, through which the auger shaft 68 extends. The shaft 68 terminates in a relatively large diameter sprocket wheel 74, over which is trained a chain 76 which is trained also over a smaller diameter sprocket wheel 78, on the drive shaft 80, of a motor 82, preferably an air-driven motor, mounted on the frame 52. When the motor 82 is in operation, the auger screw is rotated in a direction, and at a desired speed, to convey chemical material from the cylinder 34, and the open end of the tube 60, into a bypass pipe 84.

The bypass pipe 84 is connected, at its ends, to spaced points along the flow pipe 28, at opposite sides of an adjustable flow valve 86, which is incorporated in the flow pipe 28. Adjustable valves 87 are incorporated in the bypass pipe 84, where the ends thereof join the flow pipe 28. The connection of the auger tube 60 with the bypass pipe 84 is efiected through a fitting 38. The valves 86 and 87 are adapted to be adjusted to determine the desired flow of chemical material from the cylinder 34 and air or gas in which the material is entrained, whereby a controlled and variable flow of air or gas and chemical material into the drill string 16 is obtained.

The cylinder 34 is provided, adjacent to its upper end, on one side with an adjustable relief valve 92, and, 011 its other side with an adjustable air control valve 94. The air control valve 94 is connected by a hose96, with J the bypass pipe 84, at a location, as shown in FIGURE 2, which is upstream, relative to the direction of the flow of the flow of the air or gas coming from the compressor 30. This arrangement has the desired efiect of equalizing air or gas pressure, within the cylinder 34 and the flow pipe 28.

The baffie plate 46 is adapted to be elevated or depressed, relative to the auger screw 70, for the purpose of adjusting the discharge of chemical material from the injector cylinder 34 into the auger tube 69, by manipulating the handle 44.

In operation, the injector the chemical hearing air or assembly being in operation, gas passes down through the drill string 16 to the lower end of the drill string, from which it passes outwardly and upwardly, between the string and the well bore, and treats the sidewall of the well bore and the cuttings present in the bore, as hereinbefore outlined; and then passes upwardly to the well head and to a place of disposal, through he pipe 22.

What is claimed is:

1. In combination with a well bore, a well head having a discharge pipe, 2. table overlying the well head and carrying a drive, a drill string extending operatively through the drive and down through the well head into the Well bore; of a compressor having an output side, a flow pipe connected to said output side and connected to the upper end of the drill string, an injector for comminuted chemical material comprising a closed cylinder adapted to hold such material, a conveyor associated with and open to the cylinder to receive material therefrom, a bypass pipe connected to the flow pipe at points spaced along the fiow pipe, said conveyor opening into the bypass pipe.

2. The combination of claim 1, wherein an air pressure equalizing pipe is connected to the upper part of the injector cylinder and to the bypass pipe.

3. The combination of claim 1, wherein an air pressure equalizing pipe is connected to the upper part of the injector cylinder and to the bypass pipe at the upstream side of the connection of the conveyor to the bypass pipe.

4. The combination of claim 1, wherein an air pressure equalizing pipe is connected to the upper part of the injector cylinder and to the bypass pipe at the upstream side of the connection of the conveyor to the bypass pipe, said cylinder having a bottom wall formed as a horizontal auger tube having a closed end and an open end, said open end being connected to the bypass pipe, said auger tube being open at its top to the interior of the cylinder, an auger screw turning in said tube and having a shaft extending through the closed end of the auger tube, means operatively connected to the auger screw shaft.

5. A device of the character described, comprising a closed hopper, an auger conveyor at the lower part of the hopper and in material-receiving relation to the hopper, said conveyor comprising an auger tube having a closed end and an open end, an air pressure flow pipe into which material and air from the hopper is adapted to be discharged, said pipe containing air flowing in one direction only, connecting means providing communication between the open end of the auger tube and the air flow pipe, said hopper having thereon an adjustable air intake valve communicating with the interior thereof, and an adjustable air outlet valve communicating with the interior thereof, and means providing communication between the air outlet valve and said air pressure flow pipe at the upstream side of the point at which the auger tube is connected to the air flow pipe.

6. A device according to claim 5, wherein a vertically adjustable baffie plate is supported within the lower part of the hopper, said bafile plate having a peripheral edge spaced from the side wall of the hopper so as to provide a controlled discharge channel for air and material passing the baifie plate to the conveyor tube.

References Cited by the Examiner UNITED STATES PATENTS 2,345,816 4/1944 Hays 206 X 2,738,163 3/1956 Shields 175-68 2,786,652 3/1957 Wells 175-71 X 3,160,210 12/1964 Brewer 16675 CHARLES E. OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner. 

1. IN COMBINATION WITH A WELL BORE, A WELL HEAD HAVING A DISCHARGE PIPE, A TABLE OVERLYING THE WELL HEAD AND CARRYING A DRIVE, A DRILL STRING EXTENDING OPERATIVELY THROUGH THE DRIVE AND DOWN THROUGH THE WELL HEAD INTO THE WELL BORE; OF A COMPRESSOR HAVING AN OUTPUT SIDE, A FLOW PIPE CONNECTED TO SAID OUTPUT SIDE AND CONNECTED TO THE UPPER END OF THE DRILL STRING, AN INJECTOR FOR COMMINUTED CHEMICAL MATERIAL COMPRISING A CLOSED CYLINDER ADAPTED TO HOLD SUCH MATERIAL, A CONVEYOR ASSOCIATED WITH AND OPEN TO THE CYLINDER TO RECEIVE MATERIAL THEREFROM, A BYPASS PIPE CONNECTED TO THE FLOW PIPE AT POINTS SPACED ALONG THE FLOW PIPE, SAID CONVEYOR OPENING INTO THE BYPASS PIPE. 